Why does an x:Array element cause any x:Shared attribute following it to be ignored?

Question

I suspect a XAML compiler and/or WPF bug, but I want to make sure I haven\'t done something wrong here (other than trusting the XAML compiler and/or WPF, that is :) ).

Answer 1

Write <ResourceDictionary> explicitely into <Window.Resources>:

<Window x:Class="TestxSharedMenuItem.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:s="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="350" Width="525">
  <Window.Resources>
    <ResourceDictionary> <!-- modified here -->
      <x:Array x:Key="menuItemValues1" Type="{x:Type s:String}">
        <s:String>value #1</s:String>
        <s:String>value #2</s:String>
        <s:String>value #3</s:String>
      </x:Array>
      <MenuItem x:Key="menuItem1" x:Shared="False"
                ItemsSource="{StaticResource menuItemValues1}"
                Header="Shared menu item"/>
    </ResourceDictionary> <!-- modified here -->
  </Window.Resources>
  <StackPanel>
    <Menu HorizontalAlignment="Left" VerticalAlignment="Top">
      <StaticResource ResourceKey="menuItem1"/>
      <StaticResource ResourceKey="menuItem1"/>
    </Menu>
  </StackPanel>
</Window>

I had a very similar issue (actually, quite exactly the same, only with UserControl). I was desperate when I tried the above workaround :), but it worked.
I've just tried it out with your example code now, with explicit <ResourceDictionary> it works by me, without it it doesn't.